EP0047383B1 - Tête magnétique multipiste et son procédé de fabrication - Google Patents

Tête magnétique multipiste et son procédé de fabrication Download PDF

Info

Publication number
EP0047383B1
EP0047383B1 EP81105738A EP81105738A EP0047383B1 EP 0047383 B1 EP0047383 B1 EP 0047383B1 EP 81105738 A EP81105738 A EP 81105738A EP 81105738 A EP81105738 A EP 81105738A EP 0047383 B1 EP0047383 B1 EP 0047383B1
Authority
EP
European Patent Office
Prior art keywords
magnetic
substrate
bonding
pieces
fingers
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP81105738A
Other languages
German (de)
English (en)
Other versions
EP0047383A1 (fr
Inventor
William Wai-Chung Chow
Davis Stuart Fields, Jr.
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Publication of EP0047383A1 publication Critical patent/EP0047383A1/fr
Application granted granted Critical
Publication of EP0047383B1 publication Critical patent/EP0047383B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G11B5/29—Structure or manufacture of unitary devices formed of plural heads for more than one track
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G11B5/29—Structure or manufacture of unitary devices formed of plural heads for more than one track
    • G11B5/295—Manufacture
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/4902—Electromagnet, transformer or inductor
    • Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
    • Y10T29/49032—Fabricating head structure or component thereof
    • Y10T29/49048—Machining magnetic material [e.g., grinding, etching, polishing]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/4902—Electromagnet, transformer or inductor
    • Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
    • Y10T29/49032—Fabricating head structure or component thereof
    • Y10T29/49055—Fabricating head structure or component thereof with bond/laminating preformed parts, at least two magnetic

Definitions

  • This invention relates to a multitrack magnetic head and a method of manufacture thereof.
  • multitrack magnetic heads are formed by bonding single track modules, such as described in US-A-3,613,228, DE-A-2,032,354, FR-A-2,053,903 and GB-A-1,307,587. It is apparent that a multiplicity of modules must be properly aligned and have similar dimensions to result in precisely positioned tracks and accurately defined track widths, amongst other things. The steps of alignment, joinder and machining the several elements to precise predetermined dimensions are costly and time consuming. In addition, the resultant heads are not closely spaced to give a high data track density.
  • the invention seeks to provide a multitrack magnetic head that affords high data track density, that minimizes the separation between data tracks recorded on a magnetic medium, and that allows improved track definition.
  • the invention also seeks to provide a method of forming a multitrack magnetic head by which a reduction in manufacturing steps and savings in cost are realized.
  • a multitrack magnetic head comprises a row of spaced magnetic blocks and a magnetic wafer bonded to the magnetic blocks to form transducing gaps filled with non-magnetic bonding, and is characterised in that one surface of a non-magnetic substrate is joined to the row of magnetic blocks thereby forming a closure section and an adjacent surface of the substrate is bonded to the magnetic wafer, the substrate, the row of magnetic blocks and the magnetic wafer forming a compact block in which the magnetic blocks are spaced and separated by non-magnetic bonding.
  • the invention also provides an assembly from which said closure section may be cut, comprising a magnetic block and a non-magnetic bonding, characterised in that the magnetic block consists of a first magnetic piece having alternate slots and fingers, and a second magnetic piece having alternate slots and fingers, the fingers of the first and second magnetic pieces being interdigitated, with the fingers of one magnetic piece in the slots of the other magnetic piece, magnetic pieces being bonded together by non-magnetic bonding.
  • the invention further provides a method of forming said closure section involving bonding a magnetic block to a non-magnetic substrate by non-magnetic bonding and slicing the magnetic block and the substrate, characterised by the steps of forming spaced slots and fingers in first and second magnetic pieces, aligning the magnetic pieces on a non-magnetic substrate with the fingers of the first and second magnetic pieces interdigitated, the fingers of one magnetic piece being in the slots of the other magnetic piece, bonding the magnetic pieces together and to the substrate by non-magnetic bonding, and slicing the substrate and pieces across the slots and fingers to form a closure section.
  • a first ferrite comb piece 10 (Fig. 1) is formed with alternating fingers 12 and slots 14, and a second ferrite comb piece 16 is formed with similar but complementary alternating fingers 18 and slots 20.
  • the number of slots 14 corresponds to the number of fingers 18, and the number of slots 20 corresponds to the number of fingers 12.
  • the slots 14 and 20 are of the same dimensions, and are slightly larger in length and width than the fingers 12 and 18.
  • the width of each slot is approximately 700 microns, and the width of each finger is about 500 microns.
  • the depth or the height of the slots and fingers is about 1 mm, by way of example.
  • the slots may be gang sawed or wire sawed individually, by well known techniques, so that the slots and fingers have substantially parallel sides, and the fingers of one piece closely fit with the slots of the other piece, so that the fingers are interdigitated and closely spaced.
  • the ferrite pieces 10 and 16 are bonded together preferably by glass, and to a non- magnetic ceramic substrate 22, as illustrated in Fig. 2.
  • metal wires or shims 24 are fixed securely between the ferrite pieces to act as spacers.
  • the ferrite pieces 10 and 16 are positioned and aligned on the substrate prior to glass bonding. The alignment between the ferrite pieces is critical, whereas the alignment to the substrate is less significant.
  • the bonded assembly (Fig. 3) is sliced into closure sections 26 (Fig. 4), as shown by the dash lines in Fig. 3.
  • Each closure section 26 consists of a row of magnetic ferrite blocks 28 supported by a nonmagnetic substrate 30.
  • Alternate blocks 28 are parts of fingers 12 and 18, respectively.
  • the ferrite blocks are joined together and to the nonmagnetic substrate 30 by glass bonding 33.
  • the width of each ferrite block 28 determines the width of the data track, and the width of the glass bond 33 between adjacent ferrite blocks 28 establishes the separation distance between the data tracks.
  • a ferrite wafer 32 having the same length and width as the closure section 26 is cemented to the section 26 to form a write head 38 (Fig. 5).
  • a cement layer 34 between the wafer 32 and section 26 delineates the transducing gap that co-acts with a magnetic medium, such as a magnetic tape 36.
  • Multiple tracks are recorded along the moving tape 36 that correspond in width to the width of each ferrite block 28 disposed on the substrate 30.
  • a thicker cutting wheel that affords greater rigidity and less wobble may be used for cutting slots in ferrite, with the realization of accurate alignment and spacing of the multiple tracks.
  • the use of a thicker cutting wheel can greatly improve tool life.
  • the novel configuration and method allows a simplified, inexpensive approach to be employed for making multitrack magnetic heads.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Magnetic Heads (AREA)

Claims (15)

1. Une tête magnétique multipiste (38) comprenant une rangée de blocs magnétiques espacés les uns des autres (28) et une galette magnétique (32) collée aux blocs magnétiques pour constituer des entrefers transducteurs remplis de colle non magnétique (34), caractérisée en ce qu'une surface de substrat non magnétique (30) est assemblée à la rangée de blocks magnétiques (28),.formant ainsi une section de fermeture et une surface adjacente du substrat est collée à la galette magnétique (32), au substrat (30), à la rangée de blocs magnétiques (28), à la galette magnétique (32) formant un bloc compact dans lequel les blocs magnétiques (28) sont espacés et séparés les uns des autres par de la colle non magnétique (33).
2. Une tête conforme à la revendication 1, dans laquelle le substrat (30) est fait d'un matériau céramique.
3. Une tête conforme à la revendication 1 ou 2, dans laquelle les blocs magnétiques (28) sont en ferrite.
4. Une tête conforme à la revendication 1, 2 ou 3, dans laquelle les blocs magnétiques (28) sont de largeur identique.
5. Une tête conforme à l'une quelconque des revendications précédentes, dans laquelle la galette magnétique (32) est collée au substrat (30) par une colle non magnétique (34).
6. Une tête conforme à l'une quelconque des revendications précédentes, dans laquelle les blocs magnétiques (28) sont collés au substrat (30) par une colle non magnétique (33).
7. Un ensemble dont les sections de fermeture ayant les caractéristiques de la section de fermeture (26) citée à la revendication 1, 3 ou 4, peuvent être découpées, et comprenant un bloc magnétique (10, 16) et un substrat non magnétique (22) collés ensemble par une colle non magnétique (33), caractérisé en ce que le bloc magnétique (10, 16) consiste en une première pièce magnétique (10) ayant des fentes alternées (14) et des doigts alternés (18), les doigts (12, 18) de la première et de la seconde pièce magnétiques (10, 16) étant disposés en quinconce, les doigts d'une pièce magnétique ent<ant dans les fentes de l'autre pièce magnétique, les pièces magnétiques étant collées ensemble par une colle non magnétique (33).
8. Un ensemble conforme à la revendication 7, dans lequel les pièces magnétiques (10, 16) sont en ferrite.
9. Un ensemble conforme aux revendications 7 ou 8, dans lequel les doigts des deux pièces magnétiques (10, 16) sont de même largeur.
10. Une méthode de formation d'une section de fermeture présentant les caractéristiques de la section de fermeture citée à la revendication 1, comprenant le collage d'un bloc magnétique (10, 16) à un substrat non magnétique (22) par de la colle non magnétique (33) et le découpage en tranches du bloc magnétique et du substrat, caractérisée par les opérations de formation de fentes (14, 20) espacées les unes des autres et de doigts également espacés (12, 18) dans les première et seconde pièces magnétiques (10, 16) l'alignement des pièces magnétiques sur un substrat non magnétque (22) avec les doigts des première et seconde pièces magnétiques disposés en quiconce, les doigts d'une pièce magnétique étant engagés dans les fentes de l'autre pièce magnétique, le collage des pièces magnétiques ensemble et au substrat par une colle non magnétique (33), et le découpage en tranches du substrat et des pièces à travers les doigts et les fentes pour former une section de fermeture (26).
11. Une méthode conforme à la revendication 10 dans laquelle les pièces magnétiques (10, 16) sont en ferrite.
12. Une méthode conforme aux revendications 10 ou 11, dans laquelle les doigts (12, 18) des deux pièces (10, 16) sont de même largeur.
13. Une méthode conforme à la revendication 10, 11 ou 12, dans laquelle les pièces magnétiques (10, 16) sont alignées par des cales de positionnement (24) disposées entre les pièces.
14. Une méthode conforme à la revendication 10, 11, 12 ou 13, dans laquelle la colle est de verre.
15. Une méthode de formation d'une tête magnétique multipiste comprenant la formation d'une section de fermeture par une méthode conforme à l'une quelconque des revendications 10 à 14, et le collage d'une galette magnétique (32) à la section de fermeture (26) par une colle non magnétique (34).
EP81105738A 1980-09-02 1981-07-21 Tête magnétique multipiste et son procédé de fabrication Expired EP0047383B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US06/183,559 US4366518A (en) 1980-09-02 1980-09-02 Multi-track head assembly
US183559 1994-01-19

Publications (2)

Publication Number Publication Date
EP0047383A1 EP0047383A1 (fr) 1982-03-17
EP0047383B1 true EP0047383B1 (fr) 1984-07-04

Family

ID=22673328

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81105738A Expired EP0047383B1 (fr) 1980-09-02 1981-07-21 Tête magnétique multipiste et son procédé de fabrication

Country Status (4)

Country Link
US (1) US4366518A (fr)
EP (1) EP0047383B1 (fr)
JP (1) JPS5746316A (fr)
DE (1) DE3164561D1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4396967A (en) * 1981-04-13 1983-08-02 International Business Machines Corporation Multielement magnetic head assembly
US4797767A (en) * 1986-11-20 1989-01-10 American Magnetics Corporation Digital magnetic head structure
US5211734A (en) * 1989-03-31 1993-05-18 Tdk Corporation Method for making a magnetic head having surface-reinforced glass
US5055957A (en) * 1989-06-19 1991-10-08 International Business Machines Corporation Method of making low wear glass for magnetic heads

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2785038A (en) * 1952-06-02 1957-03-12 Rca Corp Magnetic transducer
US2840643A (en) * 1955-04-04 1958-06-24 Hughes Aircraft Co Integral transformer electromagnetic transducer
NL253072A (fr) * 1959-06-04
US3354540A (en) * 1961-04-07 1967-11-28 Philips Corp Method of manufacturing reliable magnetic heads having accurately predetermined dimensions
US3613228A (en) * 1969-07-02 1971-10-19 Ibm Manufacture of multielement magnetic head assemblies
US3655923A (en) * 1970-02-02 1972-04-11 Ceramic Magnetics Inc Preformed multiple track magnetic head assembly
US3943624A (en) * 1975-01-24 1976-03-16 U. S. Philips Corporation Method of manufacturing a magnetic head
GB1529967A (en) * 1977-04-28 1978-10-25 Bicc Ltd Magnetic cores

Also Published As

Publication number Publication date
JPS5746316A (en) 1982-03-16
EP0047383A1 (fr) 1982-03-17
US4366518A (en) 1982-12-28
DE3164561D1 (en) 1984-08-09
JPS6333205B2 (fr) 1988-07-04

Similar Documents

Publication Publication Date Title
KR920002579B1 (ko) 고정자기 디스크 장치용 헤드 코아 슬라이더 및 그 제조방법
EP0140977B1 (fr) Tete magnetique et son procede de fabrication
US4914805A (en) Method of manufacturing a magnetic head having a plurality of magnetic gaps
EP0047383B1 (fr) Tête magnétique multipiste et son procédé de fabrication
EP0062739B1 (fr) Assemblage de tête magnétique à éléments multiples et son procédé de fabrication
EP0116451B1 (fr) Structure de transducteur magnétique à largeur de piste réduite et procédé de fabrication
EP0179269B1 (fr) Tête magnétique
US3557445A (en) Method of fabricating slant cores
US4831481A (en) Composite magnetic head and method of manufacturing the same
JPS62197908A (ja) 磁気ヘツドの製造方法
JP2563246B2 (ja) 磁気ヘツドの製造方法
JP2566599B2 (ja) 複合型磁気ヘッドの製造方法
JPS63152003A (ja) 磁気ヘツドの製造方法
JPH0378105A (ja) マルチトラツク磁気ヘッド
JPH03288306A (ja) マルチチヤンネル磁気ヘツド及びその製造方法
JPH0377565B2 (fr)
JPH02177107A (ja) マルチトラツク磁気ヘツド及びその製造方法
JPH0731781B2 (ja) 磁気ギャップ形成方法
JPS6286527A (ja) 浮上型磁気ヘツド
JPS6192411A (ja) 磁気ヘツドの製造方法
JPS6297111A (ja) 磁気ヘツドとその製造方法
JPH0554314A (ja) 磁気ヘツドの製造方法
JPS5827569B2 (ja) 磁気ヘツドコアの製造方法
JPS63149807A (ja) 磁気ヘツド用コア及びその製造方法
JPS62217409A (ja) 磁気ヘツドおよびその製造方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR GB NL

17P Request for examination filed

Effective date: 19820407

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): DE FR GB NL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19840704

REF Corresponds to:

Ref document number: 3164561

Country of ref document: DE

Date of ref document: 19840809

ET Fr: translation filed
NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19910625

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19910723

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19920624

Year of fee payment: 12

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19930331

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19930401

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19930721

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19930721